The overall objectives of the project are to learn more about the structure, function and behavior of normal and abnormal human chromosomes using new techniques in cytogenetics and tissue culture including automated densitometry and spectrophotometry, BrdU labelling, and cytochemical techniques. Our goals are (1) to develop more quantitative approaches for analyzing chromosome banding patterns; (2) to develop and refine chromosome banding and related procedures (e.g., BrdU labelling and "in situ" hybridization) for analyzing normal and abnormal chromosomes in greater detail; (3) to better understand chromosome banding mechanisms; and (4) to apply these techniques and knowledge to the study of (a) major chromosome abnormalities, (b) chromosome mapping, (c) chromosomes in neoplastic cell lines, (d) chromosome polymorphisms, and (e) behavior of polymorphic chromosome regions in the interphase nucleus. BIBLIOGRAPHIC REFERENCES: Prescott, G.H., McCaw, B.K., Tolby, B.E., Hecht, F., Miller, R.C., Greene, A.E., Coriell, L.L.: A(1:15) translocation, balanced, 46 chromosomes. Repository identification No. GM-126. Cytogenetics Cell Genet. 14: 84-85, 1975. McCaw, B.K., Epstein, A., Kaplan, H.S., and Hecht, F.: American Burkitt's lymphoma: Chromosome 14 translocation. Clinical Research 24: 191A, 1976.